TSRT is a solution-oriented trial aiming to evaluate the effectiveness of tobacco smoke reduction among teenagers. Eligible teenagers will fit the following criteria: (a) age between 12 and 16 years old; (b) have active smoke habits in past 6 months; (c) amount of smoke exceed 10 cigarettes per week. The subjects will be recruited from our previous database for schoolchildren. Telephone interview will be used to screen the eligibility for the teenagers. Recruitment will occur over 3-month period from 2011 April to June. The procedure for TSRT is showed in figure 2. In this plan, we will recruit at least 31 asthmatic children and 31 non-asthmatic children who have active smoke habits.